Tucking mechanism for knitting machines



v F. W. ROBINSON.

' TUCKING MECHANISM FOR KNITTING MAGHINES.

APPLICATION map APR. 24. 1919.

1,425,28 PatentedAug.8,1922.

UNETED SAYS earisNr tic.

FRANK W. ROBINSON, OF READING, PENNSYLVANIA, ASSIGNOR TO THE NOLDE &

HORST 00., 0F READING, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

TUCKING TIIECHA'NISM FOR KNITTING MACHINES.

Application filed April 24,

To all whom it may concern:

Be it known that I, FRANK W. ROBINSON, a citizen of the United States, residing at the city of Reading, in the county of Berks and State of Pennsylvania, have invented certain new and useful Improvements in Tucking Mechanism for Knitting Machines, of which the following is a specification.

My invention relates to circular knitting machines, and my object is to provide improved means for intermittently effecting a tucking action of determined needles of the knitting series as may-be required to produce various desired effects.

Such'tucking action is commonly effected by providing determined needles with relatively long latches, which require a greater latch-clearing movement of such needles for ordinary knitting than is required for the needles having ordinary latches; successive loops being otherwise retained upon such relatively long latched needles so as to produce the tucking effect. My-improved construction provides for producing such effects as desired in a very simple manner in volving no variation of the needle butts upon which the knitting cam mechanism operates; as fully described in connection with the accompanying drawings illustrating my invention; the novel features of which are clearly defined in the claim.

Fig. 1 is a plan view showing a knitting cam mechanism including my improvements, in connection with a rotatable needle cylinder shown in partial horizontal section and provided with both long and short butt needles.

Fig. 2 is a diagrammatic View showing knitting cams with my tucking cam in preferred relation thereto and indicating different courses of the needles as hereinafter described.

Figs. 3 and 4 indicate respectively a needle having an ordinary latch, and a longerlatched needle which is employed as set forth both for ordinary knitting and for tucking.

The circular series of needles indicated is divided as usual into long-butt and shortbutt groups, the former of which are raised out of action during reciprocative knitting. All of the needles that are in action are operated by the usual top center cam 5 and latch-clearing cams 6 and 7 to impart there- Elpecification of Letters Patent.

Patented Aug. 8, 192523.

1919. Serial No. 292,262.

to the vertical movements normally required to successively form loops thereon and clear the same from their latches as in ordinary circular or reciprocating knitting.

In my improved construction the special long latch needles (Fig. 4) may be employed instead of ordinary latch needles (Fig. 3) in either the long or short butt groups. wherever it is desired to produce tucking effects; the required operation of these needles for either ordinary knitting or tucking being provided for by the special cam'hereinafter described irrespective of the length of the butts with which the needles are provided.

This special needle operating or tucking cam 10, as shown, is provided with a radially projecting shank 11 which is movably mounted. in guide-ways 12, 12, and is normally projected toward the needle cylinder 13 by a spring 14. The line of projection is such as to bring the cam 10 into contact with the radially extending needle butts of either the long or short butt needles that have been normally raised by the latch-clearing cam 6; so that said cam will have no effect when brought into contact with long butts 20 until after the passage of the latter, but will then be further projected by the spring 14 into contact with the short butts (the position shown in Fig. 1) so as to lie under the returning long butts. When in this partially projected position, indicated in Fig. 1, the cam 10 is adapted to raise all the long butt needles beyond the usual latch-clearing elevation imparted to them in riding upward upon the cam 6; and is at the same time fully projected by the constantly pressing spring 14 so as to position it under the short butts 21. and thereby effect a similar raising of all the returning short butt needles. The effect of this normal spring-pressed movement of the special tucking cam 10 is, therefore, to raise all the needles beyond the normal lift imparted by the usual latch-clearing earn. 6, which excess lift is sufficient to make the long latch needles as well as the others clear their loops for ordinary knitting. When it is desired that said long latch needles shall operate to produce a tuckingeffect, it is only necessary to entirely withdraw from action said tucking cam 10, so that only the ordinary latch-clearing movements will be imparted to all the needles by the ordinary cam 6; which latch-clearlng movements are insufiicient to clear the loops from thelonglatch needles until the supplemental tucking cam is again thrown into action.

The Withdrawal movement of the tucking cam 10 positively effected when desired, by means of a bell-crank lever as indicated to which required movements may be imparted through a connecting rod 26', by well knitting;

In Fig. 2 the ordinary course of all the needle butts, over the cam 6 commonlyemployed is indicated by the dotted line 30; such course being followed when the supple mental or so-called tucking cam '10 is periodically' withdrawn fromaction' so as to leave'any long latch ortucking needles with out sufficient movement to clear their loops. VVh'en the tucking cam 10 is released to' the action ofits-projecting spring 14, it may first be stopped "temporarily by contacting with the long needl e'butts passingover the cam 6'; bnt after their passage it is auto matically projected further until stopped by contact with the shorter needle butts as shown in Fig. 1, which places it under the ends of the returning long butts, where it isfree to'be fully projected automatically into the plane of the cam 6 so as to form an upward extension of the latter. When in this position-all-the' needle butts ride over it, in the course indicated by the heavier dotted line 31, thus causing the long latch needles to clear their loops and operate with the others for ordinary knitting until thecam 10 is withdrawn as determined by the opera-tionof the withdrawing lever or hell crank 25. a v

The" periodic actions thus provided for affect all the long latclrneedles similarly,

but may be varied'intime and extent' as'defsired for different effects and-purposes;the useof my invention in connection with the omission of adjacent needles to produce drop'stitche s, for duction oi attractive la'ce effects.v

a What I claim is.: l

lna knitting'm'achine comprising series of long butt and of short butt needles, certain of which are provided with relatively long latches; knitting cams including a two-part latclrclearing cam comprising a fixed part operative upon all the needles sufiiciently only to clear the loops of-the shortdatch' needles" and a movable tuckingcam top extension part normally spring-pressed toward the needles and. adapted tonautomatically position under the butts of the latter for increasing the latch-clearingmovements ime parted thereto ;=aand intermittently operated means-for positively withdrawing said tucking cam extension. 9 i a Y In testimony whereof l' 'aflix mysignature.

FRANK wfnoeinson-Q instance, enabling thepIO- 

